How much concrete do you need for a 14×14 slab?

A 14×14 ft slab poured 4 inches thick needs 2.42 cubic yards (65.3 cu ft) of concrete. With 10% extra for waste, buy 120 bags of 80 lb premix or order 2.66 yards of ready-mix.

Change the numbers

The calculator below is pre-filled for this project. Adjust any value — including feet and inches — and the results update instantly.

pcs
ftin
ftin
in
%
Add prices to estimate cost (optional)
$
$

Enter today’s prices from your store or supplier; we never guess prices for you.

Tip: enter feet and inches in separate boxes, or use decimals (10 ft 6 in = 10.5 ft).

Your results

Concrete to buy (incl. 10% extra)2.66 cu yd
80 lb bags120
60 lb bags160
40 lb bags240
Exact volume65.33 cu ft (2.42 cu yd)
How much concrete do you need for a 14×14 slab — diagram

Concrete for a 14×14 slab at different thicknesses

The slab covers 196 square feet. Every extra inch of thickness adds about 0.6 cubic yards. Quantities below include 10% for waste.

ThicknessCubic yards80 lb bags60 lb bags40 lb bags
3.5 in2.33105140210
4 in2.66120160240
5 in3.33150200300
6 in3.99180240360
8 in5.32240320480

Bags or ready-mix for this size?

At 2.66 cubic yards you are in the gray zone between bags and a truck. 120 bags of 80 lb weigh about 9,600 lb in total — get a ready-mix quote (ask about short-load fees) and compare it with the bag price before deciding.

How heavy is a 14×14 slab?

Normal-weight concrete weighs about 150 lb per cubic foot, so a 4-inch 14×14 slab weighs roughly 9,800 lb (4.9 tons) once cured. Make sure your base is compacted gravel on firm, undisturbed soil.

The math

14 ft × 14 ft × (4 in ÷ 12) = 65.33 cu ft 65.33 cu ft ÷ 27 = 2.42 cu yd +10% waste = 71.87 cu ft 71.87 ÷ 0.6 cu ft per 80 lb bag = 120 bags (rounded up)

Common questions

How many 80 lb bags of concrete for a 14x14 slab?

120 bags for a 4-inch slab including 10% extra (109 with no extra). At 6 inches thick you need 180 bags.

How many yards of concrete for a 14x14 slab 6 inches thick?

3.99 cubic yards including 10% extra, or 3.63 yards exactly.

How many 60 lb bags for a 14x14 slab?

160 bags of 60 lb concrete for a 4-inch slab with 10% extra.

Want the full method, tips and other sizes? See the concrete calculator guide.

Last reviewed November 1, 2026. Results are estimates — confirm with your supplier.

Similar sizes

12×12 slab12×16 slab12×20 slab12×24 slab16×16 slab16×20 slab18×18 slab20×20 slab

Related calculators

Paver CalculatorPavers, base gravel and bedding sand for patios and walkways.Gravel CalculatorTons and cubic yards of gravel, crushed stone or sand for driveways and paths.Fence CalculatorPosts, rails, pickets and concrete bags for a wood privacy or picket fence.